The present invention relates generally to an apparatus for sealing and severing a web of film. More specifically, the present invention relates to an apparatus for creating side seals in a web of film in a form, fill, seal packaging machine and for severing a web of film between the side seals.
Typically, form, fill, seal packaging machines are utilized to package a product in a flexible container. To this end, form, fill, seal packaging machines are used to seal pharmaceuticals, dairy products, wine, food stuffs, cosmetics, and other products in flexible containers. The form, fill seal packaging machine provides an apparatus for packaging these products in an expedient manner.
In one type of form fill, seal packaging machine a web of heat-sealable film is passed over a former or mandrel that forms the film into a tubular shape. To effect the tubular shape, the film is folded longitudinally and heat sealed along abutting longitudinal edges. The tubular shaped film is then passed around a tubular fill system that deposits the product to be packaged into the tubular shaped film. To create individual packages (hereinafter "bags") the web of film must be sealed across its width to form side seals. These side seals are usually created by a sealer that creates the second seal for one bag while making the first seal for the next bag. Typically, after the side seals are created, the web of film can then be severed between the seals to create individual bags.
There are a variety of different methods for creating side seals in a web of film. One method is to utilize a sealing bar. In a typical form, fill, seal packaging machine, the sealing bar is secured to a set of jaws that are hydraulically actuated to grip the web of film. As the jaws grip the web of film, the sealing bar is urged against the web of film melting a portion of the web of film onto itself. Typically, after the sealing bar has melted the web of film, a knife is actuated and severs the web of film between the seals to create a flexible bag.
It is also known, to create the side seals in the web of film and sever the web of film contemporaneously. For example, U.S. Pat. Application Ser. No. 889,714 to Christine discloses an apparatus and method for contemporaneously creating side seals and serving the web of film.
One of the disadvantages with some of the prior apparatus and methods for creating side seals and severing the web of film is that the process and apparatus generates a large bead of material at the molten film area where the side seal is created and accordingly a resultant bead of material is created in the final product. This resultant bead is undesirable for many reasons. The bead can cause a resultant bag to have side seals that have inconsistent and reduced strength and therefore can break and/or leak. This is especially undesirable in the pharmaceutical industry wherein parenteral and enteral pouches typically are required to withstand a 6 foot drop test.
Furthermore, a bead is undesirable in that it can generate particulate material and matter. Again, this is especially undesirable in the pharmaceutical industry wherein even a limited amount of particulate matter in the fluid being housed in the bag can cause the product to be rejected. Moreover, the resultant bead can produce an aesthetically unpleasing final product.
Accordingly, there is a need for an improved apparatus for sealing and severing a web of film in a form, fill, seal packaging machine.